[Effects of 1,25-(OH)2D3 on the secretion of growth hormone by human pituitary growth hormone-secreting tumors in vitro]

This work studied the effects of 1,25-(OH)2D3 on the secretion of growth hormone (GH) in 15 cases of human pituitary GH-secreting tumor cell cultures. At physiological doses (40-80 pg/ml) of 1,25-(OH)2D3, a GH secretion response was found in 14 cases of pituitary tumor: GH secretion was suppressed significantly in 9 of 14 cases and was markedly stimulated in only 2 of 14 cases of pituitary tumors. In the other 3 cases, the GH response was variable at different days of culture. The degree of suppression of GH secretion induced by 1,25-(OH)2D3 in all cases was 63.1 +/- 3.3% (means +/- sx of the control, and the average increase of GH secretion was 164.0 +/- 6.2% of control. There was no correlation between the type of GH reaction and the dose rang of 1,25-(OH)2D3 used in the experiment. The stimulatory effect on GH secretion did not appear after 2 weeks of culture. The results demonstrate that 1,25-(OH)2D3 at physiological doses has a direct regulatory effect (mainly suppressive) on GH secretion in most pituitary GH-secreting tumors in cell culture.

[Echocardiographic detection of fetal cardiac arrhythmias]

Using real-time directed M-mode and Doppler echocardiography we identified cardiac arrhythmias in 10 fetuses. One had signal tachycardia, one bradycardia, 5 supraventricular premature contractions, and 2 ventricular premature contractions (VPC), which were all self-limited. The diagnosis of VPC in one case was based on premature ending of foramen ovale flap's 2 nd wave on M-mode recording. All cases carried a favorable prognosis except the one with VPC who had a small ventricular septal defect overlooked prenatally. The 10 th case had II degrees atrioventricular block complicated by heart failure and died in utero. This study showed that most arrhythmias can be detected antenatally by analysing atrioventricular contraction sequences. It also proved that the characteristic M-mode pattern of foramen ovale flap is of value in evaluating the types of arrhythmias.

[Effect of dopamine and bromocriptine on secretion of growth hormone by pituitary growth hormone secreting tumor in cell culture]

This article reports the effect of dopamine (DA) and its agonist bromocriptine (CB154) on the secretion of growth hormone (GH) by pure GH-secreting pituitary tumor in cell culture as well as a comparison of the effects of these dopaminergic drugs and SMS201-295 (SMS). DA of 10(-8) and 10(-7) mol/L reduced GH secretion to 50.6 and 44.4% of the control, respectively, in 1 out of 6 tumors. CB154 of 10(-7) and 10(-6) mol/L suppressed GH secretion to 59.0 +/- 8.9% of the control in 3 out of 4 tumors. CB154 was at least 10 times less potent than SMS vis a vis GH secretion. CB154 of 10(-6) mol/L inhibited GH secretion to 63.3 +/- 13. 8% (n = 4), but SMS of 10(-7) mol/L induced GH secretion to 45.5 +/- 13.1% (n = 4), the concentration difference between CB154 and SMS was 10 times. CB154 suppressed not only GH secretion, but also GH synthesis in two tumor cell cultures. The major role of SMS in GH secretion was inhibition. The results suggest that DA and CB154 have direct inhibitory effects on GH secretion, at least in some pure pituitary GH secreting tumors. The activities of DA and CB154 are not entirely the same as that of SMS.

[Effect of the overactivated central renin-angiotensin system on the concentration of brain norepinephrine and epinephrine in stroke-prone spontaneously hypertensive rats and its significances]

The content of norepinephrine (NE) and epinephrine (E) in the brain of spontaneously hypertensive rats has proved abnormal, but the cause remained unknown. It was shown in the recent work that NE content in pons, posterior hypothalamus, nucleus caudatus and E concentration in medulla oblongata, anterior and posterior hypothalamus of 12-week old stroke-prone spontaneously hypertensive rats (SHRSP) were much higher than those of age-matched Wister-Kyoto rats (WKY). SHRSP also showed higher levels of systolic blood pressure (SBP) and brain angiotensin II (A II) than WKY. Intracerebroventricular (icv) perfusion of angiotensin-converting enzyme inhibitor captopril (20 micrograms for each time and three times for each day for four weeks) inhibited the synthesis of brain A II and reduced SBP and NE, E contents in all examined brain areas in SHRSP and WKY. However, the effects of chronically perfused captopril on SBP and brain NE, E levels in SHRSP were much more significant than in WKY. The results indicate that the modulatory effects of central renin-angiotensin system (RAS) on central adrenergic and noradrenergic system might be overactivated in SHRSP, which might partially responsible for the abnormally high levels of NE, E in some of the brain areas of SHRSP.

[Preliminary studies on the relationship between the blood pressure and renin-angiotensin system in brain and blood vessels in SHRSP]

This work analyzed the relationship between A I concentration in aorta tissue and systolic blood pressure (SBP) in stroke-prone spontaneously hypertensive rats (SHRSP) at different ages. The SBP of SHRSP increased progressively with the age until the age of 20 weeks, when the SBP of SHRSP no longer elevated but sustained at a relatively high and stable level. The A I concentration in aorta of SHRSP was much higher than that of Wistar Kyoto rats at all of the three different ages. Perfusion of captopril into the lateral cerebroventricle of SHRSP for four weeks evoked a considerable decrease of A I concentration in brain as well as a significant reduction of SBP accompanied by a decrement of A I concentration in aorta and concentration of norepinephrine and epinephrine in aorta tissue and plasma. The results further confirm the close relationship between the changed activity of renin-angiotensin system localized in blood vessels during hypertension and the pathogenesis of hypertension, and indicate the possible regulative control of A I generated from central nervous system over the production of A I from blood vessels by means of facilitating the activity of peripheral sympathetic nerve system.

[Pathologic and radiologic study of parosteal osteosarcoma. Report of 17 cases]

17 cases of parosteal osteosarcoma (POS) were studied radiologically and pathologically. It was found that the differentiation of the tumor component in the narrow basic area was the poorest and the surrounding part was the next. The tumor has the tendency to invade the cortex and then infiltrate the surrounding soft tissues in the early stage of tumor formation at the narrow basic area. We have summed up four types of essential X-ray features of cortical erosion and their pathological bases, clarified the limited ability of X-ray to reveal early cortical invasion and the range of infiltration. It seems that POS has the tendency of dedifferentiation on the whole, not being limited in one subtype.

[Analysis of residue and regression of metastatic cervical lymph nodes in NPC after radiotherapy]

Follow up results of residue and regression of metastatic cervical lymph nodes in NPC after radiotherapy are presented. All the 453 cases have been followed for more than five years. According to WHO's criteria, the relative 5 year survival rate was 43.9%. 389 of 453 had had lymph node metastases in the neck at the beginning of treatment. At the end of radiation, immediate regression rate of lymph nodes was 53.2%, which was related to lymph node size before radiotherapy. Five year survival rate of those whose lymph node metastases disappeared completely was 48.8% (group 1). There were 182 cases with residual nodes at the conclusion of radiation (140 recorded in detail). The regression rate of nodes was 96.4% (135/140) and the 5 year survival rate of these 140 patients was 40.0% (group 2). There is no significant difference and the long term results are similar in the two groups. Total recurrence rate in the neck was 4.4%: 5.3% in group 1 and 3.8% in group 2 (P greater than 0.05). The treatment results of the local cervical lesions are the same, too. In 182 cases with residual lesions, 121 with 147 clinically evaluable residual nodes, 0.5 approximately 3 cm in diameter, were followed. The regression time of these residual nodes was 2.5 approximately 2.7 months as to geometric mean (the regressive confidence limit 95%). To sum up, according to the routine cervical target dose, some nodes remaining at the of radiation seem to require no boost dose in order to avoid delayed radiation complications. But the residual nodes which recur during follow up would require a prompt retreatment.